Organo-phosphorus compounds



ORGANO-PHOSPHORUS COMPOUNDS Elbert C. Ladd and Merlin P. Harvey,Passaic, N.J., as-

signors to United States Rubber Company, New York, N.Y., a corporationof New Jersey No Drawing. Original application July 10, 1948, Ser. No.38,177.- Divided and this application Mar. 17, 1953, Ser. No. 351,494

2 Claims. (Ci. 260-461) The invention concerns a novel method for thepreparation of functionally aliphatic organo-phosphorus compounds. Morespecifically. our invention relates to a novel alkaline-catalyzedaddition reaction of a selected compound containing aphosphorus-hydrogen bond, particularly an ester of phosphorous acid orof a phosphinic acid, with a selected organic compound having amultiply-bonded carbon atom, particularly one or more carhon-carbondouble bonds or carbon-nitrogen double bonds. Our invention can beillustrated schematically by the reaction of a pentavalent phosphoruscompound having a phosphorus-hydrogen bond, with an ethylenic linkage:

Similarly with a compound containing a carbon-nitrogen double bond:

Alkali This application is a division of our copending applicationSerial No. 38,177, filed July 10, 1948, and assigned to the sameassignee as the instant application.

Heretofore the commercial utility of functionally aliphaticorgano-phosphorus compounds has been handicapped by the limited numberand the specificity of the synthetic methods available, and particularlyby the limited number of the operable phosphorus-containing reagents.The latter, for the most part, comprise phosphorus halides which, undersuitable conditions, can be made to undergo an alkylation-type ofreaction with a number of aliphatic compounds, particularly olefines.Such products can then be usefully modified by reaction with water,amines, alcohols, etc.

Now, however, as a result of our discovery, a new synthetic method ismade available whereby a compound containing a pho-sphor'ushydrogen bondmay be caused to react with a compound containing a carbon-carbon and/ora carbon-nitrogen double bond in the presence of alkali to yield afunctionally aliphatic organo-phospho-rus compound. The reactionproceeds readily and, in fact, spontaneously in many cases. Hence, itprovides a simple, direct and economical synthetic method whereby alarge variety of new functionally aliphatic organo-phosphorus compoundscan be obtained, many of which are themselves useful without furthermodification in applications such as lube-oil additives, textileassistants, surface-active agents, plasticizers, anti-oxidants fortextiles and rubber or rubber-like elastomers, rubber accelerators andcorrosion inhibitors.

In the method of our invention, the preferred phosphorus-containingstarting materials are selected from 2,971,019 Patented Feb. 7, 1961 1the class consisting of esters of phosphorous acid and esters ofphosphinic acids, having the type formula M R*Mi H-R wherein R* is aradical from the class of alkyl (e.g., methyl, ethyl, propyl, isopropyl,butyl, isobutyl, amyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl,undecyl and dodecyl), alkenyl (e.g., vinyl, allyl, methallyl, crotyl,cinnamyl, lO-undecylenyl and cyclohexenyl), aryl (e.g., phenyl,p-chlorophenyl, 3,5-dichlorophenyl, 2,4-dichlorophenyl, p-cyanophenyl,p-nitrophenyl, 3,5-dinitrophenyl, p-aminophenyl, p-hydroxyphenyl,p-methoxyphenyl, tolyl, xylyl, xenyl and naphthyl) and aralkyl (e.g.,benzyl, p-chlorobenzyl and phenethyl); M is oxygen or sulfur, R is --R*or -MR*; and P is phosphorus.

The preferred unsaturated compounds, to which the abovephosphorus-containing reagents can be added by our method, are selectedfrom the class of olefinic materials of the type formula R R C=CR R andazine compounds of the type formula YY'C=NY", wherein R is hydrogen oris alkyl, alkenyl, aryl or aralkyl as previously defined for R*, or isalpha-furyl, or alpha-thienyl, R and R are each one of the radicalshydrogen, alkyl, alkenyl, aryl, aralkyl, carboxy] or a grouphydrolyzable thereto from the class of carbalkoxy (e.g., carbomethoxy,carboethoxy, carbobutoxy, carbocyclohexoxy, carbo-2- ethylhexoxy andcarbodecoxy), carbalkenoxy (e.g., carboallyloxy and carbomethallyloxy),carbaryloxy (e.g., carbophenoxy), carbaralkoxy (e.g., carbobenzyloxy),carbonitrilo, carbamyl, including N-alkyl, N-alkenyl, N-aryl andN-aralkyl-carbamyl, and R and R may together comprise beta-ethylenoxy,i.e., CH CH O, or vinyleneoxy, i.e. -CH=CH-O-, vinylenemercapto, i.e.,CH=CH-4-, or carbanhydro; R is one of the radicals nitro, carboxyl andgroups hydrolyzable thereto, carboxymethyl and groups hydrolyzablethereto (e.g., carboxymethyl, carbalkoxymethyl and carbonitrilomethyl),

phosphono, phosphonomethyl and the corresponding alkyl, alkenyl, aryland aralkyl esters thereof (e.g., diethylphosphono, dicresylphosphonoand diphenyl phosphonomethyl), acyloxy and acyloxymethyl (e.g., acetoxy,chloroacetoxy, cyanoacetoxy, acetoxymethyl, ethylphosphato,acryloxymethyl, crotonoylmethyl, propionoxy, butyroxy, benzoyloxy,benzoyloxymethyl, p-chlorobenzoyloxy, and p-methylbenzoyloxy, includingthe analogous thio groups), acyl and acylmethyl (e.g., formyl,formylmethyl, acetyl, acetylmethyl, propionyl, butyryl, iso-' butyryl,valeroyl, acrylyl, crotonyl, cinnamyl, isobutenoyl, methanesulfonyl,benzenesulfonyl, vinylsulfonyl, benzoyl, p-methylbenzoyl,p-chlorobenzoyl, naphthoyl and phenacetyl), alkoxy and alkoxymethyl(e.g., methoxy, ethoxy, ethoxymethyl, propoxy, isopropoxy, butoxy,butoxymethyl, isobutoxy, amyloxy, hexoxy, cyclohexoxy, heptoxy, octoxy,nonoxy and decoxy), alkenyloxy and alkenyloxymethyl (e.g., vinyloxy,vinyloxymethyl, isopropenyloxy, allyloxy, allyloxymethyl,methallyloxymethyl and Z-butenoXy), aryloxy and aryloxymethyl (e.g.,phenoxy, phenoxymethyl, p-chlorophenoxy, o,p-dichlorophenoxy,p-methylphenoxy, and naphthoxy), arallc- 0x31 and aralkoxymethyl (e.g.benzyloxy, phenethoxy and benzyloxymethyl) and the correspondingthio-ether groups; each of Y and Y is one of the radicals hydrogen and-R* or Y and Y together may stand for oxygen, sulfur, tetramethylene orpentamethylene; and Y" is hy drogen, --R*, hydroxyl, acyloxy, alkoxy,alkenoxy, aryloxy, aralkoxy, the group where R is a divalent hydrocarbonradical, e.g., methylene, ethylene, propylene, trimethylene,tetramethylene,

peiitar'ri'ethylene,"hexamethylene, heptamethylene, deea- Especiallypreferred classes of reactions are as follows:

The above reactions are carried out by mixing the phosphorous reagentand the unsaturated reactant, preferably in molar ratios of from about1:1 to :1, and in the presence of a catalytic amount, e.g., 0.1 to 5.0%by weight, based on the reactants, of a basic catalyst including alkaliand alkaline earth metals, e.g., lithium, sodium, potassium, magnesiumand calcium as well as their oxides, hydroxides and alcoholates andorganic nitrogen bases, e.g., pyridine, piperidine and benzyl trimethylammonium hydroxide. Many of the reactions are so exothermic as torequire cooling, but in any case, re action temperatures in the range of25-l20 C. and more often 40-100 C. are usually suflicient to effectcompletion of the reaction within 1 to hours. In cases where thermallypolymerizable olefinic compounds such as methyl acrylate are employed,higher yields of product can usually be obtained by incremental additionof the olefinic compound to the reaction mixture.

The reaction products canbe isolated and purified by preferentialextraction, fractional distillation or crystallization.

The following examples disclose our invention in more detail. All partsare by weight.

Example 1 About 0.4 part of metallic sodium is allowed to dissolve in15.2 parts of diethyl phosphite, after which 18.5 parts of a-naphthylisocyanate are added with stirring and cooling. The reaction mixture isallowed to stand for several hours during which time it deposits asubstantially quantitative yield of white solid. The latter isrecrystallized from a mixture of ethanol and n-hexane and is then foundto melt at 93-94 C. This is a new compound believed to have thestructure Analysis.-Found, 4.48% N; 10.03% P. Theory (C H O NP) 4.56% N;10.08% P.

Example 2 Eighteen parts of N-benzylideneaniline are slowly added to 18parts of diethyl phosphite containing about 0.4 part of sodium dissolvedtherein. The reaction temperature rises to about 60C. and the reactionmixture gradually solidifies. At this point the mixture is heated on asteam bath for 0.5 hour and is then poured into water, thusprecipitating a White solid. The latter is washed with water, air-dried(yield, 31.5 parts) and recrystallized from a mixture of benzene andn-hexane, M.P. 90-91" C. This is a new compound believed to have thestructure C H CH(NHC H )P(O) OC H Analysis.-Found, 4.20% N. Theory (C HO NP) 4.38% N.

Example 3 About 05 part of metallic sodium is dissolved in 35 parts ofdiethylphosphite and 13.8 parts of phorone are slowly added. After themild exothermic reaction subsides, the reaction mixture is heated on asteam bath for 2 hours after which it is evacuated at reduced pressureto remove any unreacted starting material. The 13 parts of viscousliquid residue (n 1.4538) are believed to comprise a new compound of thestructure Analysis.Found, 14.4% P. Theory (C17H3507P2), 14.95% p.

Example 4 To a solution of about 0.4 part of metallic sodium in 27.6parts of diethyl phosphite are added 29.4 parts of Analysis.Found, 9.03%P. Theory (C14H23OqP), 9.27% P.

Example 5 To a solution of about 0.5 part of metallic sodium in p 35parts of diethyl phosphite are slowly added 45.6 parts i of di-n-butylmaleate at such a rate as to maintain the temperature of the exothermicreaction of about 55-60 C. The reaction is completed by heating on asteam bath for 2 hours, after which the reaction mixture is washed withtwo volumes of water and dried to yield 66 parts of a colorless liquid(n 1.4527) believed to be mainly a new compound of the structureAnalysis.-Found, 8.21% P. Theory (C H O P), 8.46% P.

Example 6 Analysis.-Found, 14.07% P. Theory (C H O P), 13.82% P.

Example 7 About 1.2 parts of metallic sodium are dissolved in 41.4 partsof diethyl phosphite and 15.9 parts of acrylonitrile are then addedsolwly, with sufiicient cooling to maintain the reaction temperature atabout 65 C. The reaction mixture is subsequently heated on a steam bathfor 1 hour and finally distilled to yield 30.8 parts of a water-soluble,colorless liquid, B.P. l071l1 C./0.6-0.7 mm.; 11 1.4382 which isbelieved to be a new compound of the structure (C H O) P(O)-CH CH CN.

Analysis.-F0und, 7.33% N; 16.45% P. Theory (C- H O NP), 7.33% N; 16.21%P.

In the manner of previous examples, diethyl phosphite also reacts withmesityl oxide, furan, benzalacetone, furfurylideneacetone and benzylacrylate to yield the corresponding phosphonic acid ester additionproducts.

Both our process and the products produced thereby are believed to benovel. The products obtained by the addition of diesters of phosphorousacid, such as the dialkyl esters thereof, and an unsaturated polybasicacid and compounds hydrolyzable thereto such as esters or nitrilesthereof, are particularly valuable. Examples of the latter are thealiphatic esters of alpha-(dialkyl .phosphono)-succinic acids such asare obtained, as exemplified by Examples 4 and 5 herein, by the additionreaction of a dialkyl phosphite with a di-ester of an ethylenealpha-betadicarboxylic acid such as diallyl fumarate, din-butyl maleate, etc. Theinvention presents a unique aspect in that where the unsaturatedcompound contains competing double bonds, the addition is believed totake place preferentially on the double bond alpha or beta to a carbonylgroup; thus when diallyl fumarate is used in Example 4 infra, theaddition is believed to take place fii-efe'fntiafly it the 'H'ouble bondin the fumaric aicid fe'sidue rather than at the double bonds' inthetallyl g roiifas; Inthecase of phorone (E'Xam'pl 3') the doubleborids re not competing and the addition takes place qlially'at both. 1

Having thus described our invention, what We claim and desire to protectby LettergPatent' is; 3 V

l. Diethyl 2-methyl-4-oxoPentane-Z-phosphonate. 2. Ketophosphonates havifigth e general formula r 1 in which'z' is ja lower alkyliadica l',"X is selected fro the group consisting of hy'dro'ge'iianflllowflkylzr'iidicals and X is --a;11ojwgr amyyraqica References'citedif 'the file 6 f thisfpa ft'enfi t. JUNI EE' Q 'JTATESMTEN i e,$478,390 v'He mfo 'd et a1. Aug. 9, 1949 forget; REFERENCES

2. KETOPHOSPHONATES HAVING THE GENERAL FORMULA